JPH02288251A - Cutting method of semiconductor wafer - Google Patents

Abstract

PURPOSE:To shorten a time for cutting by a method wherein an adhesive layer is formed in the part of sticking of a semiconductor wafer of a flexible sheet made of macro-molecular organic resin and in the vicinity of the part, the semiconductor wafer is stuck on the adhesive layer, the sheet is fitted to a frame for fixation and the semiconductor water is set on a wafer cutting device together with the frame and cut. CONSTITUTION:An adhesive layer 2 about 10mum thick is provided on a sheet 1 of vinyl chloride, polyethylene, polyolefin or the like and of a thickness about 100mum, except for a part at a prescribed distance from a wafer 5 to be stuck on the sheet. This sheet 1 is stuck on a frame 4 for fixation. The back of the wafer 5 is stuck on the part wherein the adhesive layer 2 is present. Then, this sheet 1 is set on a cutting device stage, together with the frame 4, by vacuum suction and complete cutting is conducted by a blade 6 for cutting, in two directions in a reciprocation mode, with the height of the blade 6 set so that the amount of cut of the sheet be about 5mum.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a method for cutting a semiconductor wafer.

[Conventional technology]

Conventionally, as one of the techniques for separating semiconductor wafers into individual pellets, there is a method using a cutting blade.

FIGS. 2(a) to 2(C) are cross-sectional views showing a conventional method for cutting a conductor wafer in the order of steps.

First, as shown in FIG. 2(a), a sheet 1 made of a base material such as polyethylene or vinyl chloride with an adhesive layer 2 is attached to a fixing frame 4 made of stainless steel or the like, and a semiconductor wafer 5 is attached. The back side is attached to the sheet 1 using the adhesive layer 2.

Next, as shown in FIG. 2(b), place it on the cutting device,
A cutting groove is made using the cutting blade 6 from the front surface to the back surface of the semiconductor wafer 5.

Next, as shown in FIG. 2(c), when one line has been cut, the blade 6 is lifted upward and the next line is cut.

[Problem to be solved by the invention]

In the conventional wafer cutting method described above, one
Immediately after the line is completely cut from the wafer surface to sheet 1 by the blade of the cutting device, the blade 6 cuts the line as shown in Fig. 2 (b).
), the upper layer of the sheet 2 is cut, and the blade 6 cuts in two directions. Normally, in the reciprocating mode where speed can be increased, the Z-axis position of the blade is important, and if left as is, the blade will break during index feeding, so as shown in Figure 2 (c), it is necessary to The blade must move to the top surface of the sheet for each line, and the Z-axis movement time for each line makes it almost the same speed as the one-way mode in which the blade cuts in one direction. This is an incomplete method for cutting pellets that does not cut into the sheet. (However, since this method requires a braking process, it has the disadvantage of increasing the number of man-hours in the subsequent process.) This method has the disadvantage of reducing process capacity by approximately 30% and requiring capital investment. .

In addition, there is a limit to increasing the Z-axis movement speed, and the positional accuracy of the Z-axis is important. If the speed is increased too much, chipping, chipping, and incomplete cutting may occur on the product, which may reduce yield. In terms of equipment, this may cause a decrease in the accuracy of the Z-axis of the blade rotating part or the occurrence of abnormalities, which may impede the operating rate and construction period.

[Means to solve the problem]

The semiconductor wafer cutting method of the present invention includes the steps of forming an adhesive layer on a flexible polymeric organic resin sheet at and near the area where the semiconductor wafer is attached, and attaching the semiconductor wafer to the adhesive layer. The method includes the steps of: attaching the sheet to a fixing frame; and placing the frame together with a wafer cutting device to cut the semiconductor wafer.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIGS. 1(a) and 1(b) are sectional views shown at the end of a process for explaining an embodiment of the present invention.

As shown in FIG. 1(a), the thickness is about 10 μm except for the part at a certain distance from the wafer 5 to be pasted onto a sheet 1 made of vinyl chloride, polyethylene, polyolefin, etc. with a thickness of around 100 μm. An adhesive layer 2 is provided. This sheet 1 is attached to a fixing frame 4.

An adhesive layer 2 is provided. Frame 4 for fixing this sheet 1
Paste it on. The back side of the wafer 5 is attached to a portion of the adhesive layer 2.

Next, as shown in FIG. 1(b), the sheet 1 is vacuum-adsorbed together with the frame 4 on the stage of a cutting device, and the cutting blade 4 cuts the sheet in a reciprocating mode in two directions until the depth of the cut is about 5 μm. The height of the blade 6 is set so that the blade 6 is cut completely.

In addition, during index feeding, since there is no adhesive layer between the wafer outer periphery and the frame 4, the Z of the blade 6
It is possible to move to the next cutting line without moving the axis, so there is no speed reduction. Further, the amount of sheet cutting can be calculated from the actual value of the amount of blade wear and can be automatically controlled.

When attaching wafers, variations in the size of the adhesive layer at the center of the sheet can be tolerated up to the area 7 surrounded by the broken line, so sheet precision is not particularly required, and deviations after attaching the wafers can be tolerated. can also be relaxed to some extent.

〔Effect of the invention〕

As explained above, in the present invention, the adhesive layer for pasting the semiconductor wafer is provided in the wafer pasting area and not in other parts, so after cutting one line of the wafer, the cutting blade is directly moved along the Z axis. It is now possible to index feed to the next line without moving, approximately 3 times faster than before.
This has the effect of reducing cutting time by 0%.

In addition, since the blade does not cut into the adhesive layer between the center of the sheet and the sheet fixing frame, less adhesive adheres to the blade, which prevents stains due to blade wear and poor cutting. It has the effect of being able to.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIGS. 1(a) and 1(b) are cross-sectional views showing the steps of an embodiment of the present invention, and FIGS. 2(a) to (C) are cross-sectional views of conventional semiconductors. FIG. 3 is a cross-sectional view showing the order of steps for explaining a wafer cutting method. DESCRIPTION OF SYMBOLS 1... Sheet, 2... Adhesive layer, 4... Frame, 5... Semiconductor wafer 6... Blade, 7...
・Adhesive layer tolerance area.

Claims (1)

[Claims] A step of forming an adhesive layer on a flexible polymeric organic resin sheet at and near the area where the semiconductor wafer is attached, a step of attaching the semiconductor wafer to the adhesive layer, and a step of attaching the sheet to a fixing frame. A method for cutting a semiconductor wafer, comprising the steps of: placing the entire frame on a wafer cutting device and cutting the semiconductor wafer.